1 | /* |
2 | * Copyright (c) 2004-2005 Todd C. Miller <[email protected]> |
3 | * |
4 | * Permission to use, copy, modify, and distribute this software for any |
5 | * purpose with or without fee is hereby granted, provided that the above |
6 | * copyright notice and this permission notice appear in all copies. |
7 | * |
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
15 | */ |
16 | |
17 | #ifndef HAVE_CLOSEFROM |
18 | |
19 | #include <sys/types.h> |
20 | #include <sys/param.h> |
21 | #include <unistd.h> |
22 | #include <stdio.h> |
23 | #ifdef HAVE_FCNTL_H |
24 | # include <fcntl.h> |
25 | #endif |
26 | #include <limits.h> |
27 | #include <stdlib.h> |
28 | #include <stddef.h> |
29 | #include <string.h> |
30 | #include <unistd.h> |
31 | #ifdef HAVE_DIRENT_H |
32 | # include <dirent.h> |
33 | # define NAMLEN(dirent) strlen((dirent)->d_name) |
34 | #else |
35 | # define dirent direct |
36 | # define NAMLEN(dirent) (dirent)->d_namlen |
37 | # ifdef HAVE_SYS_NDIR_H |
38 | # include <sys/ndir.h> |
39 | # endif |
40 | # ifdef HAVE_SYS_DIR_H |
41 | # include <sys/dir.h> |
42 | # endif |
43 | # ifdef HAVE_NDIR_H |
44 | # include <ndir.h> |
45 | # endif |
46 | #endif |
47 | |
48 | #include "compat.h" |
49 | |
50 | #ifndef OPEN_MAX |
51 | # define OPEN_MAX 256 |
52 | #endif |
53 | |
54 | #if 0 |
55 | __unused static const char rcsid[] = "$Sudo: closefrom.c,v 1.11 2006/08/17 15:26:54 millert Exp $" ; |
56 | #endif /* lint */ |
57 | |
58 | /* |
59 | * Close all file descriptors greater than or equal to lowfd. |
60 | */ |
61 | #ifdef HAVE_FCNTL_CLOSEM |
62 | void |
63 | closefrom(int lowfd) |
64 | { |
65 | (void) fcntl(lowfd, F_CLOSEM, 0); |
66 | } |
67 | #else |
68 | void |
69 | closefrom(int lowfd) |
70 | { |
71 | long fd, maxfd; |
72 | #if defined(HAVE_DIRFD) && defined(HAVE_PROC_PID) |
73 | char fdpath[PATH_MAX], *endp; |
74 | struct dirent *dent; |
75 | DIR *dirp; |
76 | int len; |
77 | |
78 | /* Check for a /proc/$$/fd directory. */ |
79 | len = snprintf(fdpath, sizeof(fdpath), "/proc/%ld/fd" , (long)getpid()); |
80 | if (len > 0 && (size_t)len <= sizeof(fdpath) && (dirp = opendir(fdpath))) { |
81 | while ((dent = readdir(dirp)) != NULL) { |
82 | fd = strtol(dent->d_name, &endp, 10); |
83 | if (dent->d_name != endp && *endp == '\0' && |
84 | fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp)) |
85 | (void) close((int) fd); |
86 | } |
87 | (void) closedir(dirp); |
88 | } else |
89 | #endif |
90 | { |
91 | /* |
92 | * Fall back on sysconf() or getdtablesize(). We avoid checking |
93 | * resource limits since it is possible to open a file descriptor |
94 | * and then drop the rlimit such that it is below the open fd. |
95 | */ |
96 | #ifdef HAVE_SYSCONF |
97 | maxfd = sysconf(_SC_OPEN_MAX); |
98 | #else |
99 | maxfd = getdtablesize(); |
100 | #endif /* HAVE_SYSCONF */ |
101 | if (maxfd < 0) |
102 | maxfd = OPEN_MAX; |
103 | |
104 | for (fd = lowfd; fd < maxfd; fd++) |
105 | (void) close((int) fd); |
106 | } |
107 | } |
108 | #endif /* !HAVE_FCNTL_CLOSEM */ |
109 | #endif /* HAVE_CLOSEFROM */ |
110 | |